A semiconductor chip may be created, for example, by a reduction projection of a mask on which a circuit pattern has been drawn onto a wafer having a resist applied thereon and by repeatedly performing processing such as an etching and a thin film formation. The progressive reduction of the scale of semiconductor processing demands the use of radiation of a further short wavelength.
Thus, a research is being made on a semiconductor exposure technique which uses a radiation of an extremely short wavelength of 13.5 nm or so and a reduction optics system. This type of technique is termed an EUVL (Extreme Ultra Violet Lithography). Hereafter, an extreme ultraviolet light will be abbreviated as “EUV light”.
Three types of EUV light sources are known: an LPP (Laser Produced Plasma: plasma produced by a laser) type light source, a DPP (Discharge Produced Plasma) type light source, and an SR (Synchrotron Radiation) type light source.
The LPP type light source is a light source which generates a plasma by irradiating a target material with a laser beam, and employs an EUV light that is emitted from this plasma. The DPP type light source is a light source which employs a plasma that is generated by an electrical discharge. The SR type light source is a light source which uses an orbital radiation. Of those three types of light sources, the LPP type light source is more likely to obtain an EUV light of a higher output power as compared to the other two types because the LPP type light source can provide an increased plasma density and can ensure a larger solid angle over which the light is collected.
A laser light source device that is configured based on the MOPA (master oscillator power amplifier) system has been proposed in order to obtain a driver pulsed laser beam of a high output power with a high repetition rate (see Patent Citation 1 and Patent Citation 2).
Moreover, a technique that uses a deformable mirror in which a variable control of a surface shape can be carried out without any inhibition to a certain extent and that arranges a wave front of a laser beam is known (see Patent Citation 3).